Julia Roberts grills David on his secret marriage

American TV host David Letterman was grilled about his secret March 19 marriage to Regina Lasko by actress Julia Roberts on the June 9

Late Show

. Roberts, 41, started the conversation on the topic by teasing Letterman, 62, on what had prompted him to tie the knot.

“I don’t know if I can look you in the eye anymore...”

Us magazine

quoted her as telling him. “Last time I saw you, you were single and then I, like, hypnotized you in my white suit or something and you went off and married Regina,” she said. Next Roberts asked him whether Lasko took his last name, and Letterman replied positively.

“So she’s Mrs. Letterman?” Roberts asked. “No, she’s Dave,” Letterman deadpanned. Julia then went on to ask him whether there was a video recording of their nuptials. “It was me, it was my son, it was Regina and the justice of the peace, and that was it,” Letterman told her. “I mean, it’s legal, that’s the most important thing, right?” he asked.

Roberts, who has been wed to filmmaker Danny Moder for nearly seven years, spoke with Letterman about marriage. “You’re bound for eternity,” she said. To which he replied: “That’s right, and never been more deeply in love.”